1. Field of the Invention
The present invention relates to devices for use in collecting an oocyte from the ovary of a patient for use in a surgically-assisted reproduction procedure, and more specifically relates to a dual-lumen oocyte collection device.
2. Discussion of the Prior Art
Surgically-assisted reproduction techniques such as in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) have become widely accepted clinical methods for the treatment of infertility. During the past several years, advances in laboratory techniques and physician expertise have significantly improved the chances for a successful pregnancy.
IVF involves the fertilization of a female oocyte or egg in vitro (outside of the womb). With GIFT, fertilization occurs in vivo (within the womb). Regardless of which of these fertilization methods is employed, oocytes are retrieved from ovarian follicles (sac-like structures on the ovaries that contain the oocytes) by either a laparoscopic or transvaginal procedure using an aspiration needle.
During an oocyte retrieval procedure, a relatively long aspiration needle is either vaginally or abdominally inserted into a patient so that the distal end of the needle is in contact with a patient's ovary. The objective is to puncture an individual follicle on the ovary and withdraw a single oocyte up through the needle. Generally, the proximal end of the needle is connected to flexible tubing which is, in turn, connected to both a test tube and a vacuum source. The vacuum source provides suction through both the tubing and the needle to allow aspiration of the oocyte from the follicle.
As follicular fluid is aspirated, it travels through the needle and tubing into the test tube. The contents of the test tube are periodically examined microscopically to determine whether an oocyte is present. In some instances, the oocyte may become lodged in the needle or in the follicle and is not easily aspirated. In such instances, it may be necessary to irrigate the follicle and needle to dislodge the oocyte and allow aspiration of the oocyte into the test tube.
Two different needle styles are currently used for oocyte retrievals. One needle style is a single-lumen device. This style requires that any irrigation that is performed be conducted through the same fluid path (or lumen) that is used for aspiration. In such instances, if an oocyte is lodged in the fluid path, the oocyte may be actually flushed back into the follicle during the irrigation procedure. Therefore, the use of a single-lumen device may create the potential of losing the oocyte during the irrigation procedure. Accordingly, some physicians prefer the use of a dual-lumen device for oocyte collection procedures. A dual-lumen device has a first fluid path, or lumen, for aspiration and a second fluid path for irrigation. The use of separate paths thereby reduces the possibility of flushing an oocyte out of the aspiration path during an irrigation procedure.
As discussed above, each oocyte is located in a fluid-filled sac or follicle. Before an oocyte can be retrieved, a physician needs to be able to accurately puncture each sac prior to retrieval without damaging or losing the oocyte. In order to cleanly puncture the sac, all oocyte collection devices include a cannula having a sharpened beveled tip. Ideally, the tip is gently inserted into the follicle to puncture the sac and release the oocyte.
Obviously, it is very important that as the tip is rotated the physician knows the orientation and location of the tip. Therefore, a need exists to provide a means for easily determining the orientation of the beveled tip and to provide a means for allowing a physician to evenly rotate the tip. Unfortunately, many oocyte collection devices contain a cannula which extends radially outwardly. Generally, any cannula which extends radially outward may make it difficult for a physician to evenly rotate the device without traumatizing the patient's ovary. If a patient's ovary is traumatized, it may further complicate the patient's ability to conceive. Thus, it is critical to evenly rotate an oocyte collection device and, thus, be able to retrieve an oocyte without traumatizing a patient's ovary.